Method and apparatus for allocating bandwidth at a network element

Abstract

Packets in a Per Hop Basis (PHB) are metered by a network element to see if they fall within a Committed Information Rate (CIR) or Committed Burst Size (CBS) for that PHB. Packets that are within the CIR or CBS for the given PHB are marked as in profile. Packets to be output over a given port that are not in profile are metered by a common Surplus Information Rate (SIR) meter, which is used to meter commonly excess packets from all PHBs configured through that port. By using a common SIR meter to meter out of profile packets for all PHBs on a given port, it is possible to allow packets from multiple PHBs to share the surplus bandwidth on a link connected to that port fairly, while not allocating bandwidth to PHBs that do not require surplus bandwidth. Token buckets may be used to implement the meters.

Description

CROSS REFERENCE TO RELATED APPLICATIONS [0001] This application is a continuation in part of prior Provisional U.S. Patent Application No. 60 / 510,474, filed Oct. 10, 2003, the content of which is hereby incorporated herein by reference.BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to communication networks and, more particularly, to a method and apparatus for allocating bandwidth at a network element. [0004] A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever. [0005] 2. Description of the Related Art [0006] Data communication networks may include various computers, servers, nodes, routers, switches, hubs, proxies, and other...

AI Technical Summary

Problems solved by technology

One drawback to this is that this solution requires the use of a considerable amount of physical memory.

Thus, implementation of a separate two rate three color meter for each PHB may thus require a considerable amount of physical memory.

Additionally, using separate meters to allocate portions of the excess bandwidth to PHBs does not allow the excess bandwidth to be shared fairly.

For example, if each PHB on a port is allocated a certain amount of excess bandwidth, PHBs with no excess data to transmit will be allocated bandwidth on the link connected to that port unnecessarily.

This solution thus results in under-utilization of the excess bandwidth.

Similarly, allowing each PHB to transmit data at a higher rate may cause over-subscription of the excess bandwidth on the link since more than one PHB may be bursting data simultaneously.

Accordingly, using separate meters per PHB does not allow multiple PHBs to share the surplus bandwidth efficiently and fairly as each separate meter will color the traffic independent of the other meters, thus potentially resulting in either too much yellow traffic or too much red traffic.

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